Martin Landau Commander John Koenig Actor Barbara Bain Dr. Helena Russell Actor Nick Tate Alan Carter Actor Catherine Schell Maya Guest Star Stuart Damon Guest Star James Laurenson Patrick Osgood Guest Star Tony Anholt Tony Verdeschi Guest Star Patrick Westwood Guest Star Pamela Stephenson Michelle Osgood Guest Star Zienia Merton Sandra Benes Guest Star Guy Rolfe Magus Guest Star Jeffery Kissoon Dr. Ben Vincent Guest Star Brian Blessed Mentor Guest Star Cassandra Harris Sares, Controller Guest Star Godfrey James Alien Transporter Guest Star Peter Duncan Cantar Guest Star Roy Marsden Alien Invisible Guest Star Leigh Lawson Zarl Guest Star John Hug Bill Fraser Guest Star Yasuko Nagazumi Yasko Guest Star Charles Crichton Director Tom Clegg Director Val Guest Director Kevin Connor Director Peter Medak Director Ray Austin Director Bob Brooks Director Michael Winder Writer Robert Lynn Director Johnny Byrne Writer Donald James Writer Terence Feely Writer Tony Barwick Writer Keith Miles Writer Lewis Schwarz Writer Fred Freiberger Writer Anthony Terpiloff Writer Christopher Penfold Writer Thom Keyes Writer Jack Ronder Writer